The present invention relates to an active inductor circuit, and more particularly an active inductor circuit as described in the preamble of claim 1.
Active inductors are already known in the art, for instance in the published European Patent Application 1248367. Therein a circuit synthesising an inductor is described, including an operational amplifier, resistors and capacitors in a specific circuit configuration. An alternative circuit is described in U.S. Pat. No. 6,028,496. A drawback of both alternatives is however is that the operational amplifiers need to be biased externally by a separate DC supply. In some applications where active inductors are needed, such as in splitters in DSL equipment where only the line feed terminals are available, there is no such external and separate DC bias or supply available.